Precision ablating method

ABSTRACT

Methods of ablating tissue in an alimentary tract are provided. The methods include advancing an ablation structure into an alimentary tract while supporting the ablation structure with an endoscope. The methods further include a step of moving at least part of the ablation structure with respect to the endoscope and toward a tissue surface, before activating the ablation structure to ablate a tissue surface.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 11/286,444 filed Nov. 23, 2005, now issued as U.S. Pat. No. 7,997,278, the full disclosure of which is fully incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to medical devices and methods of use thereof, for ablating tissue in an alimentary tract.

BACKGROUND OF THE INVENTION

Two of the major functions of the human esophagus are the transport of food from intake to the stomach and the prevention of retrograde flow of gastrointestinal contents. The retrograde flow is, in part, prevented by two esophageal sphincters which normally remain closed and which are functional rather than distinct entities. In particular, a lower esophageal sphincter normally remains closed until parasympathetic activation causes its relaxation, allowing food to pass into the stomach from the esophagus. Various types of food and other activity may cause relaxation of the sphincter, such as fatty meals, smoking and beverages having xanthene content. Certain drugs or pharmaceuticals also may cause relaxation of this lower esophageal sphincter, as well as localized trauma or other problems such as neuromuscular disorders.

Regardless, patients having such difficulties may present with clinical indications including dysphagia, or difficulty in swallowing, as well as more classic symptoms of heartburn and other similar complaints. Recurrent problems of this nature often lead to a disorder known as reflux esophagitis, consisting of esophageal mucosa damage due to the interaction of the gastric or intestinal contents with portions of the esophagus having tissue not designed to experience such interaction. As suggested above, the causative agent for such problems may vary. Esophagitis can lead to a pre-cancerous condition, known as Barrett's Esophagus, which occurs when cells of the mucosal lining become damaged and are at risk of neoplasia.

As described for example in copending, commonly owned U.S. application Ser. No. 10/754,445, filed Jan. 9, 2004, a treatment catheter having an expandable electrode support can be used for treating a circumferential region of the esophagus in order to ablate an abnormal mucosal layer of the esophagus using radiofrequency (RF) energy. When successful, the treatment results in regeneration of a normal mucosal layer substantially free from metaplastic and other damage epithelial cells characteristic of Barrett's Esophagus.

In some instances, however, such radiofrequency ablation treatment may not be entirely successful and one or more regions of abnormal mucosa may remain. Alternatively, some patients initially present to the physician with small discrete regions of abnormal mucosa that are better suited to for selective ablation rather than circumferential ablation.

SUMMARY OF THE INVENTION

In general, in one aspect, the invention features a method of ablating tissue in an alimentary tract including advancing an ablation structure into the alimentary tract, supporting the ablation structure with an endoscope within the alimentary tract, moving at least part of the ablation structure with respect to the endoscope and toward a tissue surface, and activating the ablation structure to ablate the tissue surface.

Implementations of the inventions can include one or more of the following features. The ablation structure can include a plurality of electrodes and the activating step can include applying energy to the electrodes. The step of advancing the ablation structure into the alimentary tract can include advancing the endoscope into the alimentary tract and advancing the ablation structure over the endoscope. The step of supporting the ablation structure can include inserting the endoscope into the ablation structure. In one embodiment, the ablation structure is supported by a sheath, and the step of inserting the endoscope into the ablation structure can include inserting the endoscope into the sheath. In addition, the step of inserting the endoscope into the sheath can include creating an opening in the sheath.

The step of advancing the ablation structure into the alimentary tract can alternatively include advancing the ablation structure through a channel of the endoscope. The step of supporting the ablation structure can include supporting the ablation structure with a channel of the endoscope.

Implementations of the invention can include one or more of the following features. The method of ablating tissue in an alimentary tract can further include advancing a deflection member through a channel of the endoscope. Furthermore, the step of moving at least part of the ablation structure can include deflecting the ablation structure with the deflection member. In one embodiment, the moving step includes inflating an inflatable member within the alimentary tract. In another embodiment, the moving step includes expanding a deflection member. In a further embodiment, the moving step includes moving a deflection member. In another embodiment, the moving step includes pivoting the ablation structure with respect to the endoscope.

Implementations of the invention can additionally include one or more of the following features. The method of ablating tissue in an alimentary tract can further include expanding the ablation structure from a first configuration to a second radially expanded configuration. In one embodiment, the method of the invention can further include attaching the ablation structure to the endoscope with an elastomeric sheath. In another embodiment, the ablation structure is attached to a rolled sheath and the method further includes unrolling the sheath over an outside surface of the endoscope. In a related embodiment, the unrolling step further includes unrolling the sheath over part of the ablation structure.

Implementations of the invention can additionally include one or more of the following features. The ablation structure can be attached to a channel of the endoscope. The tissue surface to be ablated can include a first treatment area, the applying step including activating the ablation structure to ablate the first treatment area, the method further including moving the ablation structure to a second area without removing the ablation structure from the patient and activating the ablation structure to ablate the second tissue area.

In general, in one aspect, the invention features a method of ablating tissue in an alimentary tract including advancing an ablation structure into the alimentary tract, supporting the ablation structure with an endoscope within the alimentary tract, bending a distal end of the endoscope to move the ablation structure into contact with a tissue surface, and activating the ablation structure to ablate the tissue surface.

Implementations of the invention can additionally include one or more of the following features. The method can further include a step of moving the ablation structure with respect to the endoscope. The moving step can include pivoting the ablation structure with respect to the endoscope. In one embodiment the moving step includes moving the ablation structure radially outward from the endoscope. In a related embodiment, the tissue surface comprises a first treatment area, the activating step including activating the ablation structure to ablate the first treatment area, the method further including moving the ablation structure to a second area without removing the ablation structure from the patient and activating the ablation structure to ablate the second tissue area. In one embodiment, the ablation structure includes a plurality of electrodes and the activating step includes applying energy to the electrodes.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which:

FIG. 1 is a view of the ablation device of the invention.

FIG. 2 is an end view of the ablation device of the invention.

FIG. 3 is an end view of the device in an expanded configuration.

FIG. 4 is a view of a coupling mechanism of the device.

FIG. 5 is a view of the ablation device of the invention showing an alternative coupling mechanism.

FIGS. 6, 7, and 8 are end views of the device in alternative expanded configurations.

FIG. 9 is a view of the ablation device of the invention in an unexpanded configuration.

FIG. 10 is a view of the ablation device of the invention in an expanded configuration.

FIGS. 11 and 12 are end views of the device in an expanded configuration.

FIG. 13 is a view of the ablation device of the invention showing a deflection member feature.

FIG. 14 is a view of the ablation device of the invention showing an alternative deflection member wherein the device is in an expanded configuration.

FIG. 15 is a view of device shown in FIG. 14 wherein the deflection member is in an unexpanded configuration.

FIG. 16 is an end view of the device in an unexpanded configuration.

FIG. 17 is an end view of the device shown in FIG. 16 in an expanded configuration.

FIG. 18 is a view of the ablation device of the invention showing an ablation structure feature.

FIG. 19 is an illustration of the ablation device of the invention combined with an endoscope system.

FIG. 20 is a schematic of view of portions of the upper digestive tract in a human, showing an esophagus including abnormal mucosa.

FIG. 21 is an illustration of the ablation device of the invention positioned within the esophagus.

FIG. 22 is a view of the ablation device of the invention including an elongated sheath feature.

FIG. 23 is a view of the device wherein an elongated sheath feature is optically transmissive.

FIG. 24 is an enlarged view of the optically transmissive feature of the device shown in FIG. 23.

FIG. 25 is a cross sectional view of the optically transmissive sheath feature of the device shown in FIGS. 23 and 24.

FIG. 26 is a view of the device including an alternative optically transmissive sheath feature and an inflation member feature in an expanded configuration.

FIG. 27 is an illustration of the ablation device of FIG. 26 positioned within an esophagus.

FIG. 28 is a view of the ablation device of the invention including a flexible tip feature.

FIG. 29 is a view of the ablation device of the invention including a slit sheath feature.

FIG. 30A is an end view of a slit sheath feature of the device wherein the sheath is in an unexpanded configuration.

FIG. 30B is an end view of a slit sheath feature of the device and an endoscope wherein the sheath is in an expanded configuration.

FIG. 31 is a view of the ablation device of the invention including an elongated sheath feature and an endoscope.

FIG. 32 is an enlarged view of the distal portion device of FIG. 31.

FIG. 33A is a cross sectional view of the device positioned within an endoscope internal working channel wherein an inflatable member feature is in an unexpanded position.

FIG. 33B is a view of the device shown in FIG. 33A wherein the inflatable member feature is in an expanded position.

FIG. 34A is a cross sectional view of the device positioned within an endoscope internal working channel wherein an expandable member feature is in an unexpanded position.

FIG. 34B is a view of the device shown in FIG. 34A wherein the expandable member feature is in an expanded position.

FIG. 35A is a cross sectional view of the device positioned within an endoscope internal working channel wherein an alternative expandable member feature is in an unexpanded position.

FIG. 35B is a view of the device shown in FIG. 35A wherein the expandable member feature is in an expanded position.

FIG. 36 is a view of the ablation device of the invention including an alternative deflection member . . . .

FIG. 37 is an illustration of the ablation device of the invention including an alternative deflection member positioned within an esophagus in a non-deflected position.

FIG. 38 is an illustration of the device shown in FIG. 37 wherein the deflection member is in a deflected position.

FIG. 39 is a cross sectional view of the ablation device of the invention showing an internal coupling mechanism feature.

FIG. 40 is a cross sectional view of the ablation device of the invention showing an alternative internal coupling mechanism and a rolled sheath feature.

FIG. 41 is an illustration showing a cross sectional view of the ablation device of the invention positioned within an esophagus.

FIG. 42 is an illustration of the ablation device of the invention positioned within an esophagus showing a rotational feature.

FIG. 43 is an illustration of the ablation device of the invention positioned within an esophagus showing a rotational feature combined with an inflation member in an expanded configuration.

FIGS. 44A, 44B and 44C are views of the ablation device of the invention showing alternative rotational features.

FIG. 45A is a view of an endoscope.

FIG. 45B is a view of the ablation device of the invention including a catheter feature.

FIG. 45C is a view of a sheath feature of the device.

FIG. 46 is a view of the ablation device of the invention including the features shown in FIGS. 45A, 45B and 45C in an assembly.

DETAILED DESCRIPTION OF THE INVENTION

A method of ablating tissue in an alimentary tract comprises the use of an ablation device including an ablation structure supported by conventional endoscopes 111, as illustrated in FIG. 19. An example of one commercially available conventional endoscope 111 is the Olympus “gastrovideoscope” model number GIF-Q160. While the specific construction of particular commercially available endoscopes may vary, as shown in FIG. 19, most endoscopes include a shaft 164 having a steerable distal end 110 and a hub or handle 162 which includes a visual channel 161 for connecting to a video screen 160 and a port 166 providing access to an inner working channel within the shaft 164. Dials, levers, or other mechanisms (not shown) will usually be provided on the handle 162 to allow an operator to selectively steer the distal end 110 of the endoscope 111 as is well known in the endoscopic arts. In accordance with the present invention, an ablation device, including an ablation structure is advanced into the alimentary tract while supported at the distal end of an endoscope. The ablation structure is deflectable toward a tissue surface and the ablation structure is activated to ablate the tissue surface. Within the alimentary tract, variously sized tissue surface sites, can selectively be ablated using the device.

In general, in one aspect a method of ablating tissue in an alimentary tract is provided. The method includes advancing an ablation structure into the alimentary tract while supporting the ablation structure with an endoscope. The method further includes moving at least part of the ablation structure with respect to the endoscope and toward a tissue surface; and activating the ablation structure to ablate the tissue surface. Moving at least part of the ablation structure with respect to the endoscope can include, but is not limited to movement toward, away from or along the endoscope. As shown in FIGS. 1, 2, 3 and 21, in one aspect a method of ablating tissue in an alimentary tract includes an ablation device 100 for ablating a tissue surface 3, wherein the device 100 includes an ablating structure, for example, an ablation structure 101 supported by an endoscope 111. The method includes ablating tissue in an alimentary tract by the steps of 1) advancing the ablation structure 101 into the alimentary tract; 2) deflecting the ablation structure 101 toward a tissue surface 3; and 3) activating the ablation structure to ablate the tissue surface 3. As shown in FIG. 1, the device 100 can additionally include a housing 107, electrical connections 109, an inflation line 113 and an inflation member 105. For the purposes of this disclosure, any components made up of mucous membrane and muscle extending between the mouth and the anus; functioning in digestion and elimination are contemplated as part of the alimentary tract. Such components include but are not limited to the esophagus, stomach, small intestine, appendix, large intestine, colon, and rectum As shown in FIGS. 20 and 21 the alimentary tract can include the esophagus 5, wherein abnormal mucosa 7 can be treated using the ablation structure 101.

The ablation structure 101, in one embodiment is an electrode structure configured and arranged to deliver energy comprising radiofrequency energy to the esophageal mucosa. It is envisioned that such an ablation structure 101 can include a plurality of electrodes. For example, two or more electrodes could be part of an ablation structure. The energy may be delivered at appropriate levels to accomplish ablation of mucosal or submucosal level tissue, or alternatively to cause injury to these tissues, while substantially preserving muscularis tissue. The term “ablation” as used herein means thermal damage to the tissue causing tissue or cell necrosis. Thermal damage can be achieved through heating tissue or cooling tissue (i.e. freezing). Typically, ablation in the present embodiments is designed to remove the entire mucosal lining in the treatment region, including the abnormal mucosa 7, for example, abnormal columnar growths, from the portions of the esophagus 5 so affected, and allow re-growth of a normal mucosal lining (see FIG. 21). Advantageously, healing is more rapid and stricture formation in the tissues is minimized when such an approach is used.

Although radiofrequency energy is one advantageous form of energy for ablation, it is recognized that other advantageous energy forms including, for example, microwave energy, or photonic or radiant sources such as infrared or ultraviolet light, the latter possibly in combination with improved sensitizing agents. Photonic sources can include semiconductor emitters, lasers, and other such sources. It is also recognized that another embodiment of this invention may utilize heatable fluid or a cooling media such as liquid nitrogen, Freon®, non CFC refrigerants or CO₂ as an ablation energy medium. For ablations using hot or cold fluids or gases, it is envisioned that the ablation system may require a means to circulate the heating/cool media from outside the patient to the heating/cooling balloon or other element and then back outside the patient again. Means for circulating media in cryosurgical probes are well known in the ablation arts. For example, and incorporated by reference herein, suitable circulating means are disclosed in U.S. Pat. No. 6,182,666 to Dobak, III; U.S. Pat. No. 6,193,644 to Dobak, III et al.; U.S. Pat. No. 6,237,355 to Li; and U.S. Pat. No. 6,572,610 to Kovalcheck et al.

In a particular embodiment, the energy delivered to the esophageal mucosa comprises radiofrequency energy that can be delivered from the energy delivery device 100. Radio frequency energy can be delivered in a number of ways. Usually, the radiofrequency energy will be delivered in a bipolar fashion from a bipolar array of electrodes positioned on the ablation structure 101, in some cases on an expandable structure, such as a balloon, frame, cage, or the like, which can expand and deploy the electrodes directly against or immediately adjacent to the mucosal tissue (e.g., through direct contact or through a dielectric membrane or other layer). Alternatively, the electrode structure may include a monopolar electrode structure which is energized by a radiofrequency power supply in combination with a return electrode typically positioned on the patient's skin, e.g., on the small of the back. In either case, the radiofrequency energy will typically be delivered at a high energy flux over a very short period of time in order to injure or ablate only the mucosal or submucosal levels of tissue without substantially heating or otherwise damaging the muscularis tissue. Wherein the ablation structure includes a plurality of electrodes, one or more of the electrodes can be bipolar or monopolar. Combinations of bipolar and monopolar electrodes are envisioned.

The ablation structure 101 can be arranged and configured in any of a number ways with regard to shape and size. Typically, the array has an area in the range from substantially 0.5 cm² to 9.0 cm². Typical shapes would include rectangular, circular or oval. In one embodiment, the ablation structure 101 has an area of 2.5 cm². In another embodiment, the ablation structure 101 has an area of 4 cm² and dimensions of 2 cm×2 cm.

The housing 107 is arranged and configured to support the ablation structure 101. The housing 107 can be made of any suitable material for withstanding the high energy flux produced by the ablation structure 101. As shown in FIGS. 1, 2, 3, 6, 11, 12, 16 and 17, in one embodiment, the housing 107 is sandwiched between the ablation structure 101 and an endoscope 111 when the ablation device 100 is supported by an endoscope 111. One end of the ablation structure 101 can be further away from the endoscope than the other end to improve ease of contact with the targeted tissue (not shown). For example, to ensure the proximal end of the ablation structure 101 makes contact with the targeted tissue, the proximal end of the electrode could be supported by a tapered housing member 107 (not shown).

The electrical connections 109 of the ablation device connects the ablation structure 101 to a power source. The electrical connections 109 can include a single wire or plurality of wires as needed to provide controlled energy delivery through the ablation structure 101. In one embodiment, the electrical connections 109 include low electrical loss wires such as litz wire.

The inflation line 113 is arranged and configured to transport an expansion medium in the form of fluid or gas to and from the inflation member 105. In one embodiment, the inflation line is a flexible tube. The inflation line 113 can be made of polymer or co-polymers, for example polyimide, polyurethane, polyethylene terephthalate (PET), polyamides (nylon) or the like. Typically, the expansion medium is a suitable fluid or gas.

The inflation member 105 is designed to deflect the ablation device 100 in relation to a tissue surface 3. The inflation member 105 can be reversibly expanded to an increased profile. In one embodiment, the inflation member 105 additionally serves as an attachment means for support of the ablation device 100 by an endoscope 111. As shown in FIGS. 2, 3, 9, 10, 11, 12, 16, 17 the inflation member 105 can be deployed from a low profile configuration or arrangement (see FIGS. 2, 9, 12, and 16) to an increased profile configuration or arrangement (see FIGS. 3, 10, 11, and 17) using the expansion medium. In preparation for ablation, when the inflation member 105 is sufficiently inflated, deflection of the ablation device 100 in relation to a tissue surface 3 can be achieved. As shown in FIGS. 3, 27, 41 and 43, in one embodiment, deflection of the ablation device 100 results in direct and sustainable contact between the ablation structure 101 of the device 100 and the tissue surface 3. For example, as shown in FIGS. 27, 41 and 43, when the inflation member 105 is sufficiently inflated, the resulting expanded profile of the inflation member 105, which contacts the tissue surface 3, results in contact by deflection between the tissue surface 3 of the inner wall of the esophagus 5 and the ablation structure 100. It is envisioned that suction can be applied in combination with the inflation member 105 to achieve contact between the ablation structure 101 and the tissue surface 3 (not shown). Suction could be achieved through the endoscope 111 or through the ablation device 100 to aid in collapsing the targeted tissue surface 3 around the ablation structure 101.

The inflation member 105 can be designed to be compliant, non-compliant or semi-compliant. The inflation member 105 can be made of a thin, flexible, bladder made of a material such as polymer, for example polyimide, polyurethane, polyethylene terephthalate (PET), or the like. In one embodiment, the inflation member is a balloon. Inflation of the inflation member 105 can be achieved through the inflation line 113 using, for example, controlled delivery of fluid or gas expansion medium. The expansion medium can include a compressible fluid such as air. The expansion medium may alternatively comprise an incompressible fluid, such as water, saline solution or the like.

As shown in FIGS. 6, 7 and 8, the inflation member 105 can be configured and arranged in a variety of ways to facilitate deflection of the ablation device 100 in relation to a tissue surface 3. For example, as shown in FIG. 6, the inflation member 105 can be eccentrically positioned in relation to the supporting endoscope 111 as well as the housing 107 and the ablation structure 101. Alternatively, as shown in FIG. 7, the inflation member 105 can be positioned concentrically in relation to the supporting endoscope 111 and the ablation structure 101 can be attached to the inflation member 105 distally from the endoscope 111. In another embodiment, as shown in FIG. 8, the inflation member 105 can be positioned between the supporting endoscope 111 and the ablation structure 101. The ablation structure 101 shown in FIGS. 7-8 can cover a range of circumferences of the endoscope 111 spanning from 5 to 360 degrees when inflation member 105 is deployed.

One method of ablating tissue in an alimentary tract can include a first step of advancing an ablation structure 101, into the alimentary tract. In a second step, the ablation structure 101 is supported with an endoscope 111 within the alimentary tract. In a third step, the ablation structure 101 is deflected toward a tissue surface 3. In a forth step, energy can be applied to the ablation structure 101 to ablate the tissue surface 3.

In another method, the step of advancing an endoscope-supported ablation structure 101 can include advancing the endoscope 111 into the alimentary tract and advancing the ablation structure 101 over the endoscope 111. For example, the endoscope 111 can be positioned relative to an ablation target tissue surface 3 after which the ablation structure 101 can be advanced over the outside of the endoscope 111 for ablating the target tissue surface 3.

In a further method, the step of supporting the ablation structure 101 with an endoscope 111 includes inserting the endoscope 111 into the ablation structure 101 (see for example, FIG. 1). In one related method, the ablation structure 101 is supported by a sheath 103 (see FIGS. 13 and 22-24, 26-29, 30B, 31, 32 and 46) and the step of inserting the endoscope 111 into the ablation structure 101 includes inserting the endoscope 111 into the sheath 103. In a further related method, the step of inserting the endoscope 111 into the sheath 103 includes creating an opening in the sheath 103 (not shown).

In a particular method, a distal portion of a sheath 103 having a smaller outer diameter than a proximal portion of the sheath 103, is adapted to be expanded when an endoscope 111 is inserted into it.

In another method, the step of advancing the ablation structure 101 into the alimentary tract includes advancing the ablation structure 101 through a channel of the endoscope 111 from either the endoscopes proximal or distal end (see as discussed below for FIGS. 33A, 34A and 35A). In yet another method, the step of supporting the ablation structure 101 comprises supporting the ablation structure 101 with a channel of the endoscope (see as discussed below for FIGS. 33A, 34A, 35A, 36-39 and 40). In a further method, a deflection structure or deflection member 150 is advanced through a channel of the endoscope 111 and the step of deflecting the ablation structure 101 toward a tissue surface 3 includes deflecting the ablation structure 101 with the deflection structure or deflection member 150 (see as discussed below for FIGS. 33A, 33B, 34A, 34B, 35A, 35B, 36-38 and 41).

As illustrated in FIGS. 33A, 34A, and 35A, variously adapted and configured ablation structures 101 can fit within and be conveyed through an endoscope internal working channel 211. In each case, the ablation structure 101 and accompanying deflection mechanism can be conveyed through the internal working channel 211 in a dimensionally compacted first configuration that is capable of expansion to a second radially expanded configuration upon exiting the distal end 110 of the endoscope 111 (See for example, FIGS. 33A, 33B, 34A, 34B, 35A and 35B).

As shown in FIG. 33B, in one embodiment, the deflection mechanism is an inflation member 105, to which the ablation structure 101 can be integrated within or mounted/attached to, for example by etching, mounting or bonding. The inflation member 105 can be, for example, a compliant, non-compliant or semi-compliant balloon.

As shown in FIGS. 34B and 35B, in another embodiment, the deflection mechanism is an expandable member 209 that can expand to a second desired arrangement and configuration. As shown in FIG. 34B, the expandable member 209, can be an expandable stent, frame or cage device, to which an ablation structure 101 is mounted or integrated. For example, where the expandable member 209 is a wire cage, the wires can be a component of a bipolar circuit to provide the ablation structure 101 feature. Alternatively, the cage can have a flexible electrode circuit bonded or can be attached to an outer or inner surface of the cage to provide an ablation structure 101 that is an electrode. As shown in FIG. 35B, the expandable member 209, can be a folded or rolled series of hoops including or having an attached ablation structure 101 that expands upon exiting the endoscope distal end 110.

As further illustrated in FIGS. 36-40, the ablation structure 101 can be supported with a channel of the endoscope 111. In one embodiment as shown in FIGS. 36-38, an ablation device 100 includes a deflection member 150 that supports an attached housing 107 and ablation structure 101. As shown in FIG. 36, the endoscope 111 includes an internal working channel 211 suitable for advancing or retreating the deflection member 150 which is connected to an internal coupling mechanism 215 of the ablation device 100. Both FIG. 36 and FIG. 38 show the deflection member 150 including a bent region of the deflection member 150 in a deployed position, wherein the deflection member 150 bent region is positioned external to the endoscope distal end 110. FIG. 37 shows the deflection member 150 in an undeployed position, wherein the deflection member 150 bent region is positioned internal to the endoscope 111. The ablation structure 101 is thus supported with a channel of the endoscope 111 (the internal working channel 211 of the endoscope 111) by way of the deflection member 150 and the connected internal coupling mechanism 215 of the ablation device 100.

In addition, when the deflection member 150 is advanced or moved proximally or distally within the endoscope internal working channel 211, the deflection member 150 is accordingly advanced through a channel of the endoscope 111. In another implementation, as shown in FIG. 41, wherein the deflection mechanism is an inflatable member 105 (shown in a deployed configuration) coupled to an inflation line 113, the inflation line 113 can be disposed within the endoscope internal working channel 211. In yet another implementation, both the inflatable member 105 (in an undeployed configuration) and inflation line 113 can be advanced within the internal working channel 211 either proximally or distally in relation to the endoscope 111 (not shown). Conductive wires 109 can pass through the working channel (not shown) or outside as shown in FIG. 36.

As shown in FIG. 40, in another implementation the endoscope 111 includes an internal working channel 211 suitable for supporting the ablation housing 107 and ablation structure 101 which are connected to an internal coupling mechanism 215 of the ablation device 100. As such, the connected ablation structure 101 is supported within a channel of the endoscope 111. Additionally as shown in FIG. 40, the housing 107 and ablation structure 101 can further be supported by an external region of the endoscope 111, wherein the internal coupling mechanism 215 is adapted and configured to position the housing 107 in contact with the external region of the endoscope 111. The internal coupling mechanism 215 can be cannulated (not shown) to facilitate use of the working channel to aspirate and inflate fluids or air.

In another ablation method, an additional step includes moving the ablation structure 101 with respect to the endoscope 111 within the alimentary tract. As illustrated in FIGS. 23, 24, 27, 28, 29, 31 and 46, and discussed below, a sheath 103 of the ablation device 100 to which the ablation structure 101 is attached can enable moving the ablation structure 101 with respect to the endoscope 111. Further, as illustrated in FIGS. 33A, 34A, 35A, 36, 37, 38 and 40, and discussed above, an internal working channel 211 of the endoscope 111 through which at least a part of the ablation device 100 is disposed can enable moving the ablations structure 101 with respect to the endoscope 111.

Referring to FIGS. 3, 27, 41 and 43, in yet another method, the step of deflecting the ablation structure 101 toward a tissue surface 3 includes inflating an inflation member 105 of the ablation device 100 within the alimentary tract. The inflation member 105 can be arranged and configured to be reversibly inflatable. The inflation member 105 can be inserted along with the ablation structure 101 into an alimentary tract 1 in a collapsed configuration and expanded upon localization at a pre-selected treatment area. In one implementation, the inflation member 105 is a balloon. For example, in FIGS. 3, 27, 41 and 43 it is shown how deflecting the ablation structure 101 toward a tissue surface 3 is achieved when the inflation member 105 is inflated or deployed. As illustrated in FIGS. 3, 27, 41 and 43, upon sufficient inflation, the inflation member 105 contacts a tissue surface 3 consequently deflecting the ablation structure 101 which contacts an opposing tissue surface 3.

As shown in FIGS. 13, 14, 15, 34, 35 and discussed above, in a further method, the step of deflecting the ablation structure 101 includes expanding a deflection structure or deflection member 150. In one implementation, as shown in FIG. 13, the ablation device 100 includes a sheath 103, wherein the sheath 103 is arranged and configured to receive the deflection member 150, the endoscope 111 and ablation structure 101 internally to the sheath 103. As shown in FIG. 13, the deflection member 150 can be a series of flexible extensions that deploy outwardly for deflecting the ablation device 100 when the deflection member 150 is extended beyond the end of the sheath 103. Conversely, the deflection member 150 can bend or fold when positioned within and moved internally to the sheath 103 (not shown). In one implementation, the deflection member 150 is a shape memory alloy, for example, Nitinol. The flexible extensions of the deflection member 150 in this embodiment can be coupled to the endoscope (as shown in FIG. 13), an elastomeric sheath 115 of the ablation device 100 (also shown in FIG. 13) or any part of the device 100, including the ablation housing 107.

As shown in FIGS. 33, 34, 35, 36, 37 and 38, and discussed above, in a further method, the step of deflecting the ablation structure 101 includes moving a deflection structure or deflection member 150.

Briefly, in each case moving the deflection 150 is used to change the deflection member 150 from a non-deployed to a deployed configuration. As shown in FIG. 18, in one embodiment, deflecting the ablation structure 101 includes a flexing point in the ablation structure 101, wherein the ablation structure 101 can deflect in response to, for example, resistance met in contacting a tissue surface 3.

As shown in FIGS. 42, 43, 44A-C and discussed in detail below, in another method, the step of deflecting the ablation structure 101 includes but it not limited to rotating, pivoting, turning or spinning the ablation structure 101 with respect to the endoscope 111. Deflection of the ablation structure 101 with respect to the endoscope 111 can occur in combination with the endoscope 111 distal end 110 deflecting with respect to the alimentary tract or without. Also, the ablation structure 101 can deflect in combination with an inflation member 105 used to achieve apposition of the ablation device 100 to the tissue. It is contemplated that the step of deflecting the ablation structure 101 may additionally include any combination of the above disclosed deflecting steps.

As shown in FIGS. 14, 15, 16, 17, 33A, 33B, 34A, 34B, 35A, 35B, 45B and 46, in another ablation method, an additional step includes moving the ablation structure 101 from a first configuration to a second radially expanded configuration. The details regarding radial expansion of the ablation structure 101 shown in FIGS. 14, 15, 16 and 17 are described below, while the details for FIGS. 33A, 33B, 34A, 34B, 35A and 35B are described above. Additionally, as shown in FIGS. 45B and 46, the ablation structure 101 can be arranged in a first configuration wherein the ablation structure 101 is coupled directly or alternatively through an housing 107 (not shown) to an inflation member 105 attached to a catheter 254. In an undeployed configuration as shown in FIGS. 45B and 46, the non-inflated inflation member 105 and ablation structure 101 have a relatively low profile in relation to the endoscope 111. When deployed, the inflation member 105 moves the ablation structure 101 to a second radially expanded configuration (not shown).

As shown in FIGS. 4, 5, 9, 10, 39, 42, 43, 44A-C, 45B and 46, in a further method, an additional step includes attaching the ablation structure 101 to the endoscope 111. As shown in FIG. 4, attachment of the ablation structure 101 can be by way of a split sheath 106. In one implementation, the split sheath 106 is coupled to the housing 107 and fits over the outside of an endoscope 111 where it can be fastened to attach the ablation structure 101 to the endoscope 111 (not shown). As shown in FIG. 5, another feature for removably attaching the ablation structure 101 to the endoscope 111 is a spiral sheath 104. As illustrated in FIG. 5, an end of the spiral sheath 104 can be connected to the housing 107, while the body of the spiral sheath 104 coils around the outside of the endoscope 111. The spiral sheath 104 can additionally coil around both the electrical connections 109 and the inflation line 113 along a length of the endoscope 111. As shown in FIGS. 9 and 10, attachment of the ablation structure 101 to the endoscope 111 can also be by way of an elastomeric sheath 115 The elastomeric sheath 115 can removably hold the ablation structure 101 in a desired position on the endoscope 111. The elastomeric sheath 115 can be arranged and configured to fit over the endoscope distal end 110. As shown in FIGS. 9 and 10, the inflation member 105 can be attached to the elastomeric sheath 115 or alternatively the inflation member 105 can also act as the “elastomeric sheath” (not shown).

In another method, the step of attaching the ablation structure 101 to the endoscope 111 includes attaching the ablation structure 101 to an outside surface of the endoscope. Alternatively, the attaching step can include, for example, attaching to an inside surface, an outside or inside feature of the endoscope, or any combinations of the above. Lubricants such as water, IPA, jelly or oil could be use to aid attachment & removal of the ablation device from the endoscope.

As shown in FIG. 40, in a further method, the step of attaching the ablation structure 101 to the endoscope 111, includes an ablation structure 101 having an attached rolled sheath 116, wherein attaching the ablation structure 101 to the endoscope 111 includes unrolling the sheath 116 over an outside surface of the endoscope 111. The rolled sheath 116 can additionally cover the electrical connections 109 of the ablation device 100 along a length of the endoscope 111 (see FIG. 40). In a related method, the ablation structure 101 is attached to the endoscope 111 by an attaching step including unrolling the rolled sheath 116 over an outside surface of the endoscope 111 and part of the ablation structure 101 (not shown).

In another method, as shown in FIG. 39, the step of attaching the ablation structure 101 to the endoscope 111 includes attaching the ablation structure 101 to a channel of the endoscope. As shown in FIG. 39, in one implementation, the housing 107 and ablation structure 101 are coupled to an internal coupling mechanism 215 that is positionable within an internal working channel 211 of the endoscope 111. The internal coupling mechanism 215 in FIG. 39 is shown as attached to the internal working channel 211 at the endoscope distal end 110. In this embodiment, the housing 107 and ablation structure 101 are shown in alignment with and coupled to an outside surface of the endoscope 111 near the distal end 110.

In one method of ablating tissue in an alimentary tract, the tissue surface 3 can include a first treatment area and activation of the ablation structure 101 step can include activation of the ablation structure 101 to ablate the first treatment area, and further include moving the ablation structure 101 to a second area without removing the ablation structure 101 from the patient and activating the ablation structure 101 to ablate the second tissue area 3 (see FIGS. 20 and 21). For example, as shown in FIG. 20, where two or more areas of the tissue surface 3 of an esophagus 5 include abnormal mucosa 7 spots, the first abnormal mucosa 20 can be ablated by directing the ablation structure 101 to the first spot and then activating the ablation structure 101 to ablate the tissue surface 3. Then, without removing the ablation structure 101 from the patient, the ablation structure 101 can be directed to the second abnormal mucosa 7 spot for ablation of the appropriate region of the tissue surface 3.

In general, in another aspect, an ablation device 100 is provided that includes an ablation structure 101 removably coupled to an endoscope distal end 110, and a deflection mechanism adapted and configured to move the ablation structure 101 toward a tissue surface 3 (see for example, FIGS. 1-3, 5-14, 16, 17, 22-24, 26-29, 32, 33A, 34A, 35A, 36, 37, 38, 41, 43 and 46).

In a related embodiment, the ablation device 100 additionally includes an ablation structure movement mechanism adapted to move the ablation structure 101 with respect to the endoscope 111. As discussed below and shown in FIGS. 22-24, 26-29, 31 and 32, the ablation structure movement mechanism can be a sheath 103 to which the ablation structure 101 is attached, wherein the sheath 103 is arranged and configured to move the ablation structure 101 with respect to an endoscope 111 received within the sheath 103. Alternatively, as discussed above and shown in FIGS. 33A, 34A, 35A, 36, 37 and 38, the ablation structure movement mechanism can be in the form of an internal coupling mechanism 215 of the ablation structure 100, wherein the ablation structure is connected to the internal coupling mechanism 215 and at least a portion of the internal coupling mechanism 215 is disposed internally to the endoscope.

In another embodiment, the ablation device 100 additionally includes a coupling mechanism designed to fit over an outside surface of an endoscope 111, to couple the ablation structure 101 with the endoscope 111. For example, as discussed above and shown in FIG. 4, a split sheath 106 coupling mechanism is provided. Additionally, as discussed above, a spiral sheath 104, an elastomeric sheath 115, a rolled sheath 116 and an internal coupling mechanism as shown in FIGS. 4, 5, (9 and 10), 40 and 39 respectively, are examples of such coupling mechanisms. In a particular embodiment, the coupling mechanism includes a sheath 103 capable of supporting the ablation structure 101. It is contemplated that the sheath 103 can be tubing, a catheter or other suitable elongate members. The sheath 103 can be arranged and configured so that it can be moved independently of an associated endoscope.

As shown in FIG. 40, in another embodiment, the sheath 103 can be arranged and configured as a rolled sheath 116 that can be unrolled over the outside surface of the endoscope. In use, a rolled sheath 116 connected to the ablation device 100, for example at substantially near the proximal end of the housing 107 (from the perspective of an operator of the device), can be unrolled from such a position and continue to be unrolled toward the proximal end 112 of the endoscope 111 (see FIG. 40). In this way, the rolled sheath 116 can be caused to contact and cover all or a portion of the length of the endoscope 111 (not shown). Additionally, as the rolled sheath 116 is unrolled along the endoscope 111, it can sandwich the electrical connections 109 between the rolled sheath 116 and the endoscope 111 (see generally FIG. 40).

In another embodiment, as shown in FIGS. 26, 27, 31 and 32, the sheath 103 can be arranged and configured to support a deflection mechanism wherein the deflection mechanism includes a deflection structure or deflection member 150. As illustrated in FIGS. 26, 27, 31 and 32, where the deflection member 150 is an inflation member 105, the inflation member 105 can be directly attached to the sheath 103. As shown in each case, the inflation member 105 is positioned opposite the placement of the ablation structure 101, which is also attached to the sheath 103. This configuration of the sheath 103 provides support for the inflation member 105 and the ablation structure 101 irrespective of the positioning of the endoscope distal end 110. For example, as shown in FIG. 26, the endoscope distal end 110 can be positioned to provide a gap between the distal end 110 and a distal end of the sheath 103 where the ablation structure 101 and inflation member 105 are positioned. In contrast, as shown in FIGS. 27, 31 and 32, the endoscope distal end 110 can extend through and beyond the distal end of the sheath 103.

In another embodiment, as shown in FIG. 22, the sheath 103 can be elongated. FIG. 22 illustrates a sheath including electrical connections 109 and an inflation line 113. It is contemplated that the sheath 103 could include pneumatic and/or over extruded wires impregnated within the sheath 103. In use, the sheath 103 can be introduced first into an alimentary tract 1, wherein the sheath 103 serves as a catheter like guide for introduction of the endoscope 111 within the sheath 103. Alternatively, the endoscope 111 could be introduced first and thereby serve as a guidewire for the sheath 103 to be introduced over. FIG. 22 also shows attachment of an inflation member 105 to the sheath 103, in an arrangement wherein the ablation structure 101 is attached to the inflation member 105 opposite the sheath 103 attachment point.

In yet another embodiment, the sheath 103 includes an optically transmissive portion 158 adapted and configured to cooperate with a visual channel 161 of an endoscope 111. For example, the sheath 103 could be made of clear, translucent or transparent polymeric tubing including PVC, acrylic and Pebax® (polyether block amide). As shown in FIG. 19, one component of an endoscope 111 can be a visual channel 161 that provides visual imaging of a tissue surface 3 as imaged from the endoscope distal end 110. For example, the transmissive portion 158 could allow visualization of the wall of an esophagus 5 through the transmissive portion 158 of the sheath 103. As shown in FIG. 24 and in the cross-section view provided in FIG. 25, the sheaths 103 shown in FIGS. 23 and 24, include an optically transmissive portion 158 arranged and configured to provide viewing of tissue surfaces 3 through the wall of the sheath 103, with the aid of an internally disposed endoscope 111 having a visual channel 161. Also shown in cross-section in FIG. 25 are portions of the sheath 103 through which electrical connections 109 and an inflation line 113 can pass. It is contemplated that these features can be imbedded into the sheath 103 inner wall or attached to the sheath 103 inner wall. As shown in FIG. 26, the sheath 103 including a transmissive portion 158 can extend past the endoscope distal tip 110. Alternatively, as shown in FIGS. 23, 24 and 27, the endoscope distal end 110 can extend distally past the transmissive portion 158 of the sheath 103.

In another implementation, the transmissive portion 158 of the sheath 103 can be reinforced structurally with coil or braid elements incorporated therein to prevent ovalization and/or collapsing of the sheath 103, particularly while deflecting the ablation device 100

As shown in FIG. 28, the sheath 103 can include a flexible tip 201 positioned on the sheath 103 distally to where the ablation structure 101 is attached to the sheath 103. The flexible curved surfaces of the flexible tip 201 can aid with accessing an alimentary tract 1.

In a further embodiment, the sheath 103 includes a slit 203 formed in a proximal portion of the sheath 103, the slit 203 being designed to open to admit an endoscope distal end 110 into the sheath 103. As shown in FIG. 29 the proximal portion of the sheath 103 can include a perforation region or slit 203. The slit 203 can extend partially of fully along the length of the sheath 103. The slit 203 enables the sheath 103 to be pulled back, or opened when, for example introducing an endoscope 111 into the sheath 103. In one implementation, as shown in FIG. 29, the sheath 103 additionally includes a locking collar 205 for locking the sheath 103 in a desired position in respect to the endoscope 111.

As shown in FIGS. 30A and 30B, the distal portion of the sheath 103 can have a smaller outer diameter than a proximal portion of the sheath 103, the distal portion of the sheath 103 being adapted and configured to be expanded when an endoscope 111 is inserted into it (not shown). This embodiment can aid in accessing an endoscope 111 in a case where the sheath 103 is advanced first into an alimentary tract 1 such as the esophagus 5. Since the distal end of the sheath 103 is smaller in diameter, but includes a slit 203, the sheath 103 can accept a larger outside diameter endoscope 111 because when the endoscope 111 is advanced, the slit 203 of the sheath 103 allows for widening of the sheath 103.

As shown in FIGS. 31 and 32, the ablation device 100 can further include electrical connections 109 extending from the ablation structure 101 to a power source or supply 159 (not shown) and the sheath 103 can be adapted and configured to support the electrical connections 109.

In general, in another aspect, a method of ablating tissue in an alimentary tract includes advancing an ablation structure 101 into the alimentary tract while supporting the ablation structure 101 with an endoscope 111. The endoscope distal end 110 can be bent to move the ablation structure 101 into contact with a tissue surface followed by activation of the ablation structure 101 to ablate the tissue surface 3 (see e.g., FIG. 42). In a particular embodiment, the ablation structure 101 includes a plurality of electrodes and the activating step includes applying energy to the electrodes.

In general, in another aspect the coupling mechanism is designed to fit over an outside surface of an endoscope 111, to couple the ablation structure 101 with the endoscope 111, rather than being for example, a sheath (as discussed above), is adapted and configured to provide a certain freedom of movement to the ablation structure 101, including but not limited to flexing and/or rotating and/or pivoting with respect to the endoscope 111 when coupled to the endoscope 111. It is contemplated that the freedom of movement is about one, two or three axis thereby providing one, two or three degrees of freedom. Examples of suitable coupling mechanisms include but are not limited to a flex joint, pin joint, u joint, ball joint or any combination thereof. The following described coupling mechanism embodiments advantageously provide for a substantially uniform apposition force between a supporting endoscope 111 and an ablation structure 101 when localized at a target tissue surface 3.

As shown in FIGS. 42, 43 and 44A and B, the coupling mechanism can be a ring 250 attached to the housing 107 and the endoscope 111, wherein the housing 107 is adapted and configured to flex, rotate or pivot about the ring 250. For example, as illustrated in FIG. 42 (see detailed view in FIG. 44B), where the ablation device 100 is coupled to a deflectable distal end 110 of an endoscope 111 by a ring 250, when the device 100 is deflected toward the tissue surface 3 of, for example, the esophagus 5, the housing 107 upon contact aligns the ablation structure 101 with the tissue surface 3 by flexing, rotating or pivoting about the ring 250 coupling. Advantageously, sufficient contact pressure provided by deflection of the distal end 110 of the endoscope 101 can produce a desired degree of contact between the ablation structure 101 and the tissue surface 3, irrespective of the precise alignment of the distal end 112 in respect to a plane of the tissue surface 3 to be treated. For the purposes of this disclosure, a “desired degree of contact” or “desired contact” between the ablation structure 101 and the tissue surface 3, includes complete or substantial contact between all or a portion of a predetermined target on the tissue surface 3 (e.g. abnormal mucosa 7) by all or a portion of the ablation structure 101.

As shown in FIG. 43, in a different yet related embodiment, where the deflection mechanism of the ablation device 100 is an inflatable member 105, a ring 250 coupling allows for flexing, rotating or pivoting of the housing 107 and ablation structure 101. As in the previous case, sufficient contact pressure provided through deflection, here by the inflatable member 105, can produce a desired degree of contact between the ablation structure 101 and the tissue surface 3. Again, advantageously, the desired contact can be achieved irrespective of the precise alignment of the deflected endoscope 111 distal end 110 in respect to a plane of the tissue surface 3 to be treated, because of the flexing, rotating or pivoting provided by the ring 250 coupling.

As shown in FIG. 44C, in a related embodiment, the coupling mechanism between the ablation device 100 and an endoscope 111 can be an elastic band 252, wherein the housing 107 of the device 100 is flexibly coupled to the elastic band 252. For example, as illustrated in FIG. 44C, where the ablation device 100 is coupled to a distal end 110 of an endoscope 111 by an elastic band 252, when the device 100 is deflected toward a tissue surface 3 of, for example, the esophagus 5 (not shown), alignment between the housing 107 and accordingly the ablation structure 101 and the tissue surface 3, can be achieved by flexing about the elastic band 252 coupling. Once more, advantageously, the desired contact can be achieved irrespective of the precise alignment of the deflected endoscope 111 distal end 110 in respect to a plane of the tissue surface 3 to be treated, because of the flexing provided by the elastic band 252 coupling.

As shown in FIG. 44A, in another related embodiment, the coupling mechanism between the ablation device 100 and an endoscope 111 can be a combination of a ring 250 and an elastic band 252, wherein the housing 107 of the device 100 is coupled to the elastic band 252. For example, as illustrated in FIG. 44A, where the ablation device 100 is coupled to a distal end 110 of an endoscope 111 by an elastic band 252, when the device 100 is deflected toward a tissue surface 3 of, for example, the esophagus 5 (not shown), alignment between the housing 107 and accordingly the ablation structure 101, and the tissue surface 3 by flexing, rotating or pivoting about the ring 250 and the elastic band 252 coupling can be achieved. Again, advantageously, the desired contact can be achieved irrespective of the precise alignment of the deflected endoscope 111 distal end 110 in respect to a plane of the tissue surface 3 to be treated, because of the flexing rotating or pivoting provided by the elastic band 252 coupling.

In another embodiment, the ablation device 100 additionally includes an alternative coupling mechanism between the ablation device 100 and an endoscope 111 that is arranged and configured to fit within a channel of an endoscope 111. The coupling mechanism can be an internal coupling mechanism 215 and can be configured and arranged to couple the ablation structure 101 within an internal working channel 211 of an endoscope 111 (see FIG. 36 and as discussed above)

As shown in FIGS. 33A, 33B, 34A, 34B, 35A and 35B, in one embodiment of such a coupling mechanism, the ablation structure 101 is adapted and configured to fit within the endoscope internal working channel 211. Additionally, as shown in FIGS. 33A, 33B, 34A, 34B, 35A and 35B, in a related embodiment, the deflection mechanism is also adapted and configured to fit within the endoscope internal working channel 211.

In each of the embodiments described above and shown in FIGS. 33A, 33B, 34A, 34B, 35A and 35B, after expansion of the inflatable member 105 or expandable member 209 and subsequent treatment of a target tissue 3, the coupling means can further serve as a means to draw, pull or retrieve the ablation structure 101 and deflection mechanism back into the endoscope internal working channel 211. Furthermore, in addition to providing coupling of the ablation structure 101 with the endoscope internal working channel 112, the coupling mechanism can include electrical connections 109 to provide energy to the ablation structure 101.

In a related embodiment, again wherein the ablation device 100 additionally includes a coupling mechanism adapted and configured to fit within a channel of an endoscope 111, the coupling mechanism can include a shape memory member and the deflection mechanism can include a bent portion of the shape memory member. As shown in FIGS. 36, 37 and 38, the coupling mechanism can be an internal coupling mechanism 215. As shown, the internal coupling mechanism 215 can be disposed within an endoscope internal working channel 211 and extend beyond the endoscope distal end 100. Additionally, the internal coupling mechanism 215 can be connected to a deflection mechanism that is a deflection member 150. The deflection member 150 can include a bent portion and can be connected to the housing 107. As shown in FIG. 37 and discussed above, the bent portion of the deflection member 150 can be disposed within the endoscope internal working channel 211, causing the ablation structure 101 to move into a non-deployed position. Upon advancing the internal coupling mechanism 215 toward the endoscope distal end 110, the shape memory nature of the deflection member 150 facilitates deployment of the ablation structure 101 to a position suitable for ablation.

In general, in one aspect, the ablation structure 101 of the ablation device 100 includes an optically transmissive portion 158 adapted and configured to cooperate with a visual channel of an endoscope 111. As shown in FIGS. 23, 24, 25, 26 and 27 and discussed above, the optically transmissive portion 158 can be a sheath 103 of the ablation device 100.

In one embodiment, the ablation structure 101 of the ablation device 100 is further adapted and configured to move from a first configuration to a second radially expanded configuration. As shown in FIGS. 14, 15, 16 and 17, the ablation structure 101 and housing 107 can be designed to reversibly move from a first less radially expanded configuration (see FIGS. 15 and 16) to a second radially expanded configuration useful for ablation. Foldable or deflectable configurations that provide for reversible radial expansion of the housing 107 and the ablation structure 101 can facilitate access to tissue surfaces because of reduced size. Additionally, foldable or deflectable configurations are helpful in regard to cleaning, introduction, retrieval, and repositioning of the device in the alimentary tract.

The ablation device 100 shown in FIGS. 14 and 15 includes an ablation structure actuator 152 arranged and configured to move the ablation structure 101 from the first configuration (see FIG. 15) to a second radially expanded configuration (see FIG. 16). As shown in FIGS. 14 and 15, the actuator 152 can be elongate and designed to work with a receiver 154 arranged and configured to receive the actuator 152. The actuator 152 can be a wire, rod or other suitable elongate structure. Alternatively, the actuator 152 can be a hydraulic actuation means with or without a balloon component. In a particular embodiment, the actuator 152 is a stiffening wire.

As illustrated in FIG. 15 before the actuator 152 is disposed within the portion of receiver 154 attached to the housing 107, both the housing 107 and the ablation structure 101 are in a first position having a first configuration. As illustrated in FIG. 14, after the actuator 152 is partially or fully introduced into the receiver 154, the housing 107 and the ablation structure 101 are consequently changed to a second radially expanded configuration relative to the first configuration. Introduction of the actuator 152 into the receiver 154 can force the portions of the housing 107 and ablation structure 101 flanking the receiver 154 to expand radially (see FIG. 14). In one embodiment, the housing 107 is heat set in a flexed first configuration suitable for positioning the ablation device 100 near a target tissue surface 3. After a target tissue surface 3 has been reached, the actuator 152 can be introduced into the receiver 154 to achieve the second radially expanded configuration which is useful for ablation of the tissue surface 3.

In a related alternative embodiment, the housing 107 and ablation structure 101 include an unconstrained shape that is radially expanded and includes one or more flex points to allow for collapsed or reduced radial expansion when positioned distally to the distal end 110 of an endoscope 111 and compressed by an elastomeric sheath 115 (not shown).

As shown in FIGS. 16 and 17, in another embodiment, the ablation structure 101 of the ablation device 100 is adapted and configured to move from a first configuration to a second radially expanded configuration wherein the ablation device 100 further includes an expandable member 156. As illustrated in FIG. 16, the expandable member 156 can be positioned between the housing 107 and the endoscope 111, where in unexpanded form, the ablation structure 101 is accordingly configured in a first configuration. Upon expansion of the expandable member 156, the ablation structure 101 configuration is changed to a second radially expanded configuration (see FIG. 17).

In one embodiment, the deflection mechanism of the ablation device 100 includes an inflatable inflation member 105. As shown in FIGS. 3, 16, 17, 22, 23, 24, 26, 27, 32, 33A-B, 41, 43, 45 and 46, and discussed above, the inflation member 105 can facilitate deflection of the device 100 in relation to a tissue surface 3.

In another embodiment, the deflection mechanism includes an expandable member 156 (see FIGS. 34B and 35B, discussed in detail above). As shown in FIG. 34B, the expandable member 209, can be an expandable stent, frame or cage device. As shown in FIG. 35B, the expandable member 209, can be an expanded series of connected hoops, that can be folded or rolled prior to expansion.

In another advantageous embodiment, the ablation device 100 further comprises a torque transmission member adapted and configured to transmit torque from a proximal end of the endoscope 111 to the ablation structure 101 to rotate the ablation structure 101 about a central axis of the endoscope 111. In a particular embodiment, the torque transmission member includes first and second interlocking members adapted to resist relative movement between the endoscope 111 and the ablation structure 101 about the central axis. As shown in FIGS. 45B, 45C and 46, in one embodiment the first interlocking member is a key 258 and the second interlocking member is a keyway 256. In one embodiment, the first interlocking member is attached to a sheath 103 surrounding the endoscope 111 and the second interlocking member is attached to a catheter 254 supporting the ablation structure 101. For example, as shown in FIGS. 45B, 45C and 46, the key 258 can be attached to a sheath 103 surrounding the endoscope 111 and the keyway 256 can be attached to a catheter 254 supporting the ablation structure 101. In a further related embodiment, the catheter 254 and sheath 103 are arranged and configured for relative movement along the central axis of the endoscope 111.

The sheath 103 can be, for example, an elastomeric sheath wherein the key 258 is attached to the outside of the sheath 103 substantially along a longitudinal axis of the sheath 103 (see FIG. 45C).

In use, this embodiment provides for a 1-to-1 torque transmission of the ablation device 100/endoscope 111 assembly when the endoscope proximal end 112 is manipulated, while also providing for positioning of the ablation structure 101 either proximal or distal to the endoscope distal end 110 in situ. Additionally, the sheath 103 can be pre-loaded into the catheter 254 or loaded separately

In general, in one aspect, an ablation device 100 is provided including an ablation structure 101, and a coupling mechanism adapted to removably couple the ablation structure 101 to a distal end 110 of an endoscope 111 and to permit the ablation structure 101 to rotate and/or pivot with respect to the endoscope when coupled to the endoscope (see generally FIG. 21). Various related embodiments wherein, for example, the coupling mechanism comprises a ring 250 and the ablation structure 101 is adapted to rotate and/or pivot about the ring 250; wherein the coupling mechanism comprises an elastic band 252 adapted to flex to permit the ablation structure 101 to rotate and/or pivot; wherein the ablation device 100 further includes a deflection mechanism adapted and configured to move the ablation structure 101 toward a tissue surface 3; and, wherein such a deflection mechanism includes an inflatable member, have been set out in detail above.

While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby. 

What is claimed is:
 1. A method of ablating tissue in an alimentary tract comprising: advancing an ablation structure through a channel of an endoscope and into the alimentary tract, wherein the ablation structure is disposed on an arcuate frame and includes an arcuate bipolar electrode array configured to selectively ablate a portion of the alimentary tract less than a full circumferential section of the alimentary tract, and wherein the arcuate frame is configured to expand from a dimensionally compacted configuration upon exiting the endoscope channel; supporting the ablation structure with the endoscope within the alimentary tract; moving at least part of the ablation structure toward a tissue surface; and activating the ablation structure to ablate the tissue surface less than the full circumferential section of the alimentary tract.
 2. The method of claim 1, wherein the advancing comprises moving the ablation structure out of a distal end of the endoscope.
 3. The method of claim 1, further comprising advancing a deflection member through a channel of the endoscope, the moving comprising deflecting the ablation structure with respect to the endoscope with the deflection member.
 4. The method of claim 1, wherein the moving comprises expanding a deflection member.
 5. The method of claim 1, wherein the moving comprises moving a deflection member.
 6. The method of claim 1, further comprising withdrawing the ablation structure back into the endoscope channel utilizing an internal coupling mechanism. 